I use a commercial brand called Heat'rs...they're produced in Show Low,
Arizona.  Their website is www.forestenergy.com and their phone # is
(800)246-3192.  I get them at woodstove dealers/suppliers or large
home-improvement stores (primarily Home Depot), though once I found
them at a grocery store.  They run about $3.00 for a 40-lb bag, and
I've found they are tax-free as they are considered heating fuel even
if we do use them for fritter-litter!  Your best bet is to stock up in
fall/winter/spring as they are hard to come by in the summer months...
that seems to be when I always run out.  ;p
 
They don't 'spoil', just make sure they stay dry; that's the most
important thing.  A bag lasts me a couple months, but that varies
depending on the number of furchins I have...right now I have 3, and so
I'll be going thru them faster.  I bought two bags to start with when
they first became available this fall, prior to that I paid a fortune for
a 30-lb bag of recycled newspaper pellets since I failed to plan ahead
last spring. :(
 
When I first started using them I just mixed the previous litter with
some of the pellets and kept adding more and more pellets.  Mine didn't
seem to mind the change at all, and I've never had a problem with the
fuzzbrats trying to eat them, although they do like to dig in them when
they're brand new, and my one dirty weasel preferred to sleep in her
litter box and poop in the cage corner, incorrigible brat!  ;)
 
Hope this info helps... :)
 
daoine o', aka *the ferret queen*
Dweezil, Razzle, and Monty
~Missing Sylvi and Loki~
[Posted in FML issue 3944]